1. Field of the Invention
The invention relates to a panel, particularly a floor panel, which exhibits a spring on at least one side and a groove on the opposite side, which features are designed in such a way that several panels can be combined by insertion into each other, while the spring/groove connection is provided with interlocking means that prevents displacement of two panels against the direction of the connection.
2. Background Description
Panels of this kind are disclosed in, e.g., WO97/47834 and JP 3-169967. These panels can be combined without the use of, e.g., glue on the substructure or without the need for additional connecting members. The connecting edges of two floor panels can be inserted one into the other by insertion along a straight line, parallel to the substructure; here the form-fit of the interlocking means prevents the panels from sliding counter to the direction of connection. The corresponding design of the spring/groove is called the xe2x80x9cclick profilexe2x80x9d. So that the form-fit between the interlocking means can take effect, the spring of the first panel bends the lower lip of the groove of the second panel in the direction of the lower side when the two panels are brought together for insertion.
Panels of this kind are generally produced from wood materials, particularly HDF or MDF. Consequently the elasticity of the lower lip cannot be precisely adjusted. Particularly when two panels are interlocked improperly it is impossible to exclude the possibility that the lower lip will be bent too far and will break, a circumstance that may not necessarily be noticed when the panels are being laid, but that will result in a poor connection or none at all.
Known from WO 94/01628 are connecting elements for floor panels that are attached to the panels on the lower side and that make possible a snap connection. At one connecting element there is a groove and at the other a spring. The spring of the connecting element is slotted, so as to form two elastic lips. Each lip is provided with a wedge-shaped heel. The groove of the other connecting element exhibits corresponding undercuts. When the two connecting elements are interlocked, the two lips of the spring are pressed together and then spring apart when the projections engage with the undercuts.
DE 72 07 395 discloses a connecting element by means of which two panels with swallow-tailed grooves can be connected. In keeping with the swallow-tailed shape of the grooves, the connecting element has the shape of a wedge and has a center slit on either side. By means of the slit, the connecting element can be pressed together so that the shape complementary to the swallowtail of the groove is canceled and the spring component can be laterally inserted into the groove. The legs then spring back and fill out the groove.
Proceeding from this description of the problem, the goal is to improve the initially described panel. The problem is solved in a panel of the generic type in that the spring exhibits a slit that runs parallel to the upper side and the groove, at its bottom, exhibits a wedge-shaped projection which engages with the slit when the panels are brought together.
With this design the spring is given two parts and becomes elastic. The two spring parts are pressed together upon insertion into the groove of another panel. When the interlocking means engage, the two parts spring apart and the form-fitting connection is produced.
The tip of the projection rests at same the level as the slit in the spring and when the two panels are brought together it engages with the slit and forces the two spring parts outward, so that there is a secure lock. At the same time, stability in the spring-groove connection is increased, since the two parts of the spring are supported at their free ends.
The elasticity of the two spring parts increases with the depth of the slit, so that slit will ideally extend over the entire width of the spring.
The interlocking means will ideally be formed by a projection that is provided on the spring and that projects toward the lower side of the panel, and by a recess provided in the groove. As an alternative, the projection can be provided in the groove and the recess in the spring.
It is advantageous if the projection and the recess are so positioned in relationship to each other that two inserted panels are in a stressed state, at least at the point of connection of the upper sides. This will create a tight connection on the upper side, which forms the panel""s visible surface, and will prevent the penetration of moisture, without the need for a further seal.
The spring and the groove can be positioned on both the longitudinal and the lateral sides of the panel, so that the same connecting technology can be applied on all sides, particularly when a floor is laid, thereby facilitating the process of laying the floor.